Wax production



A. L SKLAR WAX PRODUCTION May 1,-1945.

Filed Oct. 2, 1942 I pressure at a temperature above normal.

wax is obtained in solid form from the extracting Patented May 1 1945 UNITED STATES PATENT Fr es wax rnonnc'rron' n w Lee Sklar, Washington. D. c. Application October 2, 1942, Serial No. mates (c1. ecu-412.8) i This invention relates to the production of wax- 6 Claims.

and is particularly directed to an improved meth od for the eflicient and economical separation of a useful wax from sugar-cane. I a

It has long been known that sugar cane contains a waxy substance, largely localized upon a the outer rind of the cane, and a number of proposals have bee n made for isolating this wax, which-is commonly known as sugar cane wax.

It has been found thata substantial proportion of the wax content of the sugarcane is carried along with the juice obtained in. the usual crushing and expressing operations, and that this wax is eventually found in the filter cake resulting from the defecating and clarifying operations and known in theindustry as .mud."

I have now found'that the sugar cane wax can beveryemciently separated from materials containing the same, such as the filter cake or mud obtained in the defecationof the-cane juice, by. with liquid sulfur di-' extracting the materials omde. I

The extraction is preferably carried out under The liquid by evaporating off the sulfur dioxide or preferablyby cooling the extracting liquidand decanting or filtering the liquid portion from the wax which separates out on cooling.

In-order to provide an economical extraction terial to a series of extractions on the countercurrent principle beginning the treatment of fresh material with liquid sulfur dioxide which is already nearly saturated with wax byv contact with previously extracted material and finally of substantially the entire wax content of the a material, it is advantageous to subject the .ma-

treating the nearly exhausted material with fresh liquid sulfur dioxide.

The number of extractions necessary and the relative volumes of liquid sulfur dioxide required valves so that liquid can be passe'd-inseri es through any desired set of the extractors similar to the well-knownarrangement of diifuser batteries for the extraction of sugar values from I sugar beets. The extractors are fitted with a false bottom for supporting the wax-containing material to be extracted.

Liquid sulfur dioxide may be supplied to any of the extractors from reservoir l0 through pipe,

I l Steam is supplied to the heaters through pipe l2. Liquid may be passed from any selector extractor through any selected group of the remaining extractors. Returnpipe l3 and the individual feed pipes connecting pipe H with the extractors make it possible to start orend the extraction cycle at any of the extractors, and by means of pipe' l4 liquid may be transferred from any of the extractors to any of the crystallizers C1, C2-Cn, which need not correspond in number'with the number of extractors. In normal "operation one of the extractors is being unloaded and reloaded with a fresh'charge of wax-containing material while the material in the other extractors is undergoing the counter-current ex 25 traction.

The sulfur dioxide recoverysystem includes a still [5, a compressor l6 and a condenser l'l. In the operation of the apparatus, a charge of dry wax-containing material, such as the mud described above, is placed in one of the extractors in place of an exhausted charge, nearly saturated liquid from the'extraotor with the most recently changed material is. then passed into the freshly charged extractor, and so on, in series, while a fresh batch of liquid sulfur dioxide'is L fed from. the reservoir intothe extractor containing the most nearly exhausted charge. The contents of the reactors are maintained at. a suit-v able temperature, for example, about 75 0., by adjusting the steam supply to the external heaters. The liquid coming from thelast charged exwill largely depend onlthe temperature at which tractor, now substantially saturated with wax, is now passed to one of the crystallizers C1, Ca- -Cn,

and a new extraction cycle is started.

The'solution in the crystallizer is cooled to approximately --10 C. by pumping'ofl sulfur dioxide vapor through compressor lfiand condenser l'l until the pressure in the crystallizer is 5 approximately atmospheric. Due to the cooling, the major portion of the wax content of the solution crystallizes out. The liquid remaining in the crystalli'zer is then drawn off through pipe l8 to the liquid sulfur dioxide reservoir.

In order to avoid an undue accumulation of impurities in the liquid sulfur dioxide, a portion of the liquid from the crystallizers is continuously or intermittently Ied to still 15 where it is vaporized and the vapors returned to the system through compressor i6 and condenser 11.

The material remaining in the crystaliizers after withdrawal of the mother liquor is a lightcolored, flufiy material which readily decomposes on heating-to form a brownish wax, typically hayinga melting point of 75 C., an iodine number of 36 and a saponification number of 116. This wax is very hard and is capable of producing a brilliant gloss. A typical dry sugar cane mud will yield about 10% by weight of the wax.

1. A method of producing sugar cane wax which comprises extracting material containing sugar cane wax with liquid sulfur dioxide to produce a solution of the wax in liquid sulfur dioxide, Separating the solution from the extracted material, and thereafter separating the wax from the solution.

2. A method of producing sugar cane wax which comprises extracting material containing sugar cane wax with liquid sulfur dioxide at a temperature substantially above normal to produce a solution of the wax in liquid sulfur dioxide,

. separating the solution from the extracted material, and thereafter separating the wax from the solution.

3. A method of producing sugar cane wax which comprises extracting material containing sugar cane wax with liquid sulfur dioxide at a 2 I y a 2,375,142

temperature'substantialiy above normal to produce a solution of the wax in liquid sulfur dioxide, separating the solution from the extracted material, and thereafter separating the wax from 5 the solution by cooling the solution.

4. A method of producing sugar cane wax which comprises extracting material containing sugar cane wax with liquid sulfur dioxide at a temperature substantially above normal to produce a solution of the wax in liquid sulfur dioxide,

separating the solution from the extracted material, and thereafter cooling the solution by partial evaporation of the sulfur dioxide and k separating the residual liquid from the solid material formed on cooling.

5. A method of producing sugar cane wax which comprises extracting sugar cane mud with liquid sulfur dioxide at a temperature substam tially above normal, separating the solution of wax thereby obtained from the residual mud, and

thereafter separating the wax from the solution.

6. A method of producing sugar cane wax which comprises passing a series of batches of liquid sulfur dioxide succemvely into contact with a series of batches of sugar cane mud of progressively increasing wax content at a temperature substantially above normal until the liquid sulfur dioxide is substantially saturated with wax and the mud is substantially free of wax, and separating the wax from the solution. 

